LAMENESS IN THE HIND LEG. 81 



the tigliteuing of the teuclinous apparatus fixing the joints, 

 it being assisted by the triceps femoris. There is at first 

 a gradual increasing flexion of the joints, due to the 

 relaxation of the patellar muscles, the joints of the limb 

 flexing as the weight of the body is received by the leg, until 

 the hoof is about perpendicularly below the hip joint ; now 

 the energetic contractions of the extensors of the hip, stifle 

 aud hock joints, which means practically all the muscles of 

 the leg, lengthen it and move the body forward. 



Swinging-leg lameness of the hind-leg can be divided 

 into three main groups. 



Swinging-leg lameness in general depends on diseased 

 conditions of the active organs of locomotion, primarily the 

 muscles ; but disease of the joints, tendons and their 

 sheaths may also produce it. 



Swinging-leg lameness, with retarded movement and 

 shortening of the anterior half of the step, is present in : 



1. Inflammation and rupture of the ilio-psoas. The 

 hind-legs are dragged, rising and lying down is painful, and 

 therefore cautiously done. 



2. Painful states in the tensor fasciae lata. 



3. Inflammatory processes in the gluteal muscles, 

 especially the tendon of the middle gluteus. 



4 Contraction of the muscular elements of the limb, due 

 to severe and continued work, bring on a dragging gait ; it is 

 characterized by the fact that the phalangeal muscles are 

 also affected, causing the fetlock to be upright and to 

 knuckle over at the moment the function of the supporting- 

 leg sets in. 



5. Paralysis of the sciatic nerve and its collateral 

 branches. 



